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Tubing between PD carbs sohc 78 k8

tdubsy

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Hey everyone,

I'm doing a full rebuild on my PD 42 carbs.

Ive spent the last few hours scrolling the internet trying to figure out the type of tubing and size between the carb bodies to no avail.

Im guessing the yellowed tube is a vacuum tube and the black is fuel line.

Does anyone have a better idea, Especially the sizing?

Thanks
 

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The yellowed tube is the bowl vents, they have fuel fumes so it will still need to be fuel resistant. The black is the fuel tubes for the accelerator pump nozzles. Best place to find this sizes of tubing is a small engine repair shop, most automotive parts stores dont carry fuel line this small.
 
Thanks,

Do you know the sizes of these tubes? and could I use the same fuel tube for the bowl vents?
 
Just take one of the carbs with you so you can verify the tube fits. As long as its fuel rated hose it will work.
 
Would I have issues if I managed to jam a slightly smaller tube on? Like how some people have issues with fuel lines that are too small.

I'm trying to keep the bike as OEM spec as possible to avoid any troubleshooting down the line. that's why I was hoping for the exact sizes.

Thanks`
 
just redid mine, I put in 3/16" fuel line for both. the black ones for the accelerator pump rails also should have inserts that cut the inside diameter down to increase the pressure for the accelerator jets that shoot a squirt of gas into the carb when you hit the throttle (which depresses the accelerator pump on carb #2). if you don't have them in the ones you have then someone may have replaced them already and left them out, if that is the case then you can make some up out of 3/16" outer diameter and 11/64 inner diameter copper tubing. just cut one at .35" and one at .45" and then put the 2 of them between each set of carbs on your black lines. your yellowish tubes are 3/16" also but you can use the same fuel line. if your brass tubes are blocked and not letting a stream of gas go into the carbs you can use a .010" high E guitar string to clear them out. ( which is the size of your slow idle jet too)
 
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